Probable using of tabulated force fields in Gulp

GULP
1

Dear Julian, Hi.
As in the molecular editor tool, “Avogadro”, which one can choose force fields from: GAFF, Ghemical, MMFF94, MMFF94s, UFF; to minimize the energies, is it possible in gulp to use such a library instead of using the parameters in the input files?
If yes, where can I find an input template?
Thanks in advance.
Best regards,
Mahmoud

2

Hi Mahmoud
Rather than answer directly, I thought it would be better to coach you in how you can find answers yourself as this is a valuable skill to have for a researcher:

  1. Read the manual or look in the help text that comes with GULP or is available on line.
  2. Look at the example files that come with the code
  3. Look around the files that come with GULP (or search using “find” or equivalent)
  4. Type GULP and UFF (for example) into a search engine
    If you have no luck with any of these then I’ll explain further.
    Best regards,
    Julian
3

Hi Julian.
Thank you so much for your reply.
More or less I usually use my learned skills to find answers to questions by myself, but sometimes time matters and one tries to find a shortcut :wink: .
I had found example49 which had used the uff library and also had quick look at the UG, but did not succeed to find the simple answer. I just needed, in the first step of uff usage, a simple input template for a mono-atomic structure, and then refer to example49.
Best regards,
Mahmoud

4

Hi Mahmoud,
If you want to save time then you just buy a copy of Materials Studio and then it will write the inputs for you. Not sure there is much to add to example49 - you just need to atom type your structure and off you go…
Regards,
Julian

5

Dear Julian,
Hi.
Thank you so much for your tips and helps; suffices to try.
I highly appreciate your kind helps even though “time” matters very much for you handling lots of things, and I am so sorry if I took your time.
Best wishes,
Mahmoud